When sourcing expansive powder, the most critical factor is the temperature grade. Suppliers typically offer different versions (e.g., 5°C–15°C, 15°C–25°C, and 25°C–35°C); using the wrong grade can lead to 'blow-outs' (sudden steam eruptions) or failure to crack. You must also verify the expansive pressure, which should ideally be between 50 to 150 MPa depending on whether you are breaking reinforced concrete or hard granite. Ensure the reaction time aligns with your project needs, usually ranging from 2 to 8 hours for initial cracking.